Thats scary, but thank for posting because it's an important heads up. Maybe it's only with the chrome ones, i don't know. But this will surely make me check mine. It also reminds me i'd better start checking all important screws regualrly !
In a similar incident about a week after i got my bike i was riding home from work when i heard a clunking sound. Sounded like something was loose like the battery and bouncing when i'd hit bumpy areas in the road. i wrote it off as being something normal that i hadn't noticed before with the bike being new and all. Got home and as i was pushing the bike into the cramped area i park it i noticed the front brake disc badly grinding against the pad. Looked down and the left caliper was hanging there by one bolt, the other having vibrated out and was gone ! The dealer had swapped front fenders with another bike before i took delievery because my bike's fender had a scratch in it. So apparently they hadn't tightened them, or at least not enough. Had the other bolt came out the caliper probably would have caught in the wheel and i'd have done a swan dive over the handlbars.
There's a ultra important lesson in all this....check bolts on a regular basis and torque as necassary !!! Thanks for the reminder.